124 OUR NATIONAL FORESTS 



in keeping the area burned over to the lowest possi- 

 ble acreage. 



Causes of Forest Fires on the National Forests. 

 Forest fires on the National Forests originate in 

 many different ways. In 1917, lightning caused 

 27 per cent. ; unknown agencies, ' 17 per cent. ; 

 campers, 17 per cent.; incendiaries, 12 per cent.; 

 railroads, 13 per cent. ; brush burning, 7 per cent. ; 

 saw mills, 3 per cent., and all other causes, 4 per 

 cent. Thus it will be seen that a very large per- 

 centage, at least 60 per cent., of the fires are at- 

 tributable to human agencies and are therefore pre- 

 ventable. At least 27 per cent, of the fires, those 

 attributed to lightning, are not preventable, and 

 the only way to combat those is for the Forest officer 

 to get to them as soon as possible after they get 

 started. The preventable fires, however, may be 

 arrested at their source, that is, by popular educa- 

 tion dealing with the use of fire in the woods these 

 causes can be greatly reduced and, in time, no doubt, 

 eliminated. Therefore, the fire protection problem 

 immediately resolves itself into two almost distinct 

 phases of action fire prevention and fire control. 



Just how these various agencies start fires may 

 be of interest. Railroads cause fires by their loco- 



